During an initial psychiatric evaluation on a 65-year-old man who is new to the practice, the patient expresses concern about his left foot "shaking." One of the differential diagnoses for dementia of Alzheimer’s type is Parkinson's disease. Which physical exam finding would be expected?

Choice A reason: Parkinsonian tremor is not absent at rest; a lack of tremor would be inconsistent with early Parkinson's disease. Choice B reason: Resting tremor is a hallmark feature of Parkinson’s disease, often unilateral initially, and can continue even during voluntary movement, which fits the patient’s presentation. Choice C reason: Tremor present only during movement describes intention tremor, which is characteristic of cerebellar disorders, not Parkinson’s disease. Choice D reason: Tremor worse with movement but present at rest does not align with the classic presentation of Parkinson’s disease, where resting tremor predominates.